Sealing rotary piston engine



United tates This invefntion relates to rotary piston engines and `isparticularly concerned with a sealing deyice for such an engine,comprising, if desired, a plurality of sealing bars disposedrespectively in grooves formed in the piston.

lt is known to seal the piston of a reta-ry piston engine with respectto the cyiinder by means of bars disposed periphernily of the piston. inorder to obtain seaiinig engagement of these sealing bars With the wallof the cylinder even at low speed of revolntion of the piston, springshave been placed in back of the seal-ing bars for biasing them radiallytoward the cylinder Wall in sealing eng. "ernent therewith. However, ithas not always bee pos e until now, despite this radially directedSpring bias, to eqnaiize or conipensate the play of a bar within itsg'oove, which necessarily results in the fabrication, so that fiutteringof the sealing bars occurred nnayoidabiy particnlarly at high speed ofrevolution.

ln order to overcome this drawback, it is in accordance With theinvention proposed to press the respective sealing bars in tangentialdirection against the corresponding groove ianks by means of Springforce applied thereto. it is entrely feasible to apply the Spring forcewhich operates in tangential direction so that it also cxerts a radialforce of the respective se. i' bar, tnns ene ng on the sealing bartangential as well as radial pressure by one and the same Springelement.

The sealing bars are at speed of revolntion pressed against the cylinderwall by the centifugal force, so that a further Spring biasing may beomit-ted at such high speeds.

Et is accordingly further proposed to cancel at increasing speed ofreyolntion the radial force compenent of the Spring bias. This is in sirele manner obtained, for exarnple, by arranging the corresponding Springin a plane extending obliquely to the radial plane and arrangng the endthereof, which rests against the piston, with snfi'icient play torelieve it of the load of :ta force, while securng the other end againstradial dis'riacement by m abutrnent on the piston. rElie springs areadvantcgeonsly provide-d within recesses formed respectively in thepiston and the senling bar. In another e-nibodinient, the radialiyeffective Component of the biasing Spring means is cancelled at highSpeed revoluti-sn of the piston, by the action of a lever arm which isin engagernent with one end of a radially effective biasing Spring.

Further details and features of the invention will appecr from thedescription of embodiments thereof which is rendered below withreference to the accompanying rewing.

FlG. 1 shows part of a piston having a sealing bar iased by an obliqnelyarranged Spring; and

FG. 2 shows part of a piston provided ith a sealing bar biased radiallyand a Spring, the action of which is cancel-led at high piston speed andbiased tangent-ialiy by an auxiliary Spring.

The senling bar i shown in FG. 1 is movably disposed within the groove 2of the piston 3 and is pressed against its neighboring surfaces -inradial as well as in tangential atent ICQ direction by the Spring 4which is disposed obliquely to the rndial plane extending -in thedirection R. The radial bias Component of the Spring 4 ceases to beeffective at speed of revolntion of the piston owing to placement ofsuch Spring as previously explained.

The sealing bar di shown in FG. 2 is positioned within a Iradial .grooyeLZ forrned in the piston 13, but the radial and tangential Spring biasis in :this arrangernent snbdivided, ernploying a tangen-tially actingSpring 14 positioned in a lateral recess extending frorn the radialgroove forrned in the piston i and a radia-lly acting Spring i arrangedat the bottom of the groove 35.2. The action of the Spring 15 iseffectiye only at relatively low Speed of revolntion of the piston. Athigher speed of revointion, the sealing bar 11 will be e'lfected bycentrifugal force, pressing it in sealing i :ncagement with the cylinderwall, and the radial biasing action of the Spring 15 will cease as itabuts against a lever pivoted at i? which engagcs the edge .116 of theradial groove 12. r,fine sealing bar i is thus at higher speed ofrovo-lution of .ne piston held in sealing engagement with the cylinderwall only by the action of centrifugal force while the action of thetangental bias Spring 1-43- continnes.

Changes may be niade Within the scope and spirit of the appended ciairnswhich deiine what is believed to be new des' ed to have protected byLetters Patent.

I claim:

1. A device for Sealing the piston of a rotary piston engine, comprisingat least one seaiing bar provided in a radie-.l groove forined in thepiston, and Spring means operatively disposed between said piston andsealing bar for ener-tino on the latter respectively a radiallyeffective force operative to hold the free end of such Sealing bar inseaiing engagernent With the wall of the cylinder and a tangentiallyeffective force which is effective to press said sealing bar against thefianks of said radial grcove, said spriniy means being Constructed tohave a limited Spring movement with respect to the radially effectiveforce thereof whereby such force is cancelled by the action ofcentrifngal force acting on the sealing bar.

2. A sealing device according to clairn 1, where-in said Spring meanscomprises a single Spring having its axis disposed at an angle to thedirec ion of movement of said sealing bar, operetive to exert bothtangential and radial pressure on said sealing bar, said Spring having alength to provide snfr'icient play to relieve it of the load ofcentrifugal force.

3. A sealing device according to claim 1, wherein said Spring meanscomprises two springs, one of which is operatively disposed between saidpiston and Sealirig bar to exert tangential force on the latter, and theother Spring being operatively disposed between said piston and Sesiingbar to exert a radial force on the latter, and a pivoted lever disposedbetween said last mentioned Spring and the sealing bar, said leyer beingConstructed -to engage a portion of said piston, at higher speeds ofrevolntion, operative to relieve the force exerted by said Spring onsaid sealing bar.

References Cited in the file of this patent UNITED STATES PATENTS488,517 Clernents et al. May 2, 1905 '1,997,184 Ruehman Apr. 9, 19352,78,884 Deschanips May 24, 1955 2,977,888 Livermore Apr. 4, 1961FOREIGN PATENTS 553,569 France May 25, 1923

1. A DEVICE FOR SEALING THE PISTON OF A ROTARY PISTON ENGINE, COMPRISINGAT LEAST ONE SEALING BAR PROVIDED IN A RADIAL GROOVE FORMED IN THEPISTON, AND SPRING MEANS OPERATIVELY DISPOSED BETWEEN SAID PISTON ANDSEALING BAR FOR EXERTING ON THE LATTER RESPECTIVELY A RADIALLY EFFECTIVEFORCE OPERATIVE TO HOLD THE FREE END OF SUCH SEALING BAR IN SEALINGENGAGEMENT WITH THE WALL OF THE CYLINDER AND A TANGENTIALLY EFFECTIVEFORCE WHICH IS EFFECTIVE TO PRESS SAID SEALING BAR AGAINST THE FLANKS OFSAID RADIAL GROOVE, SAID SPRING MEANS BEING CONSTRUCTED TO HAVE ALIMITED SPRING MOVEMENT WITH RESPECT TO THE RADIALLY EFFECTIVE FORCETHEREOF WHEREBY SUCH FORCE IS CANCELLED BY THE ACTION OF CENTRIFUGALFORCE ACTING ON THE SEALING BAR.